Pumped storage hydropower (PSH) development continues to accelerate, driven by projects in construction and development stages. PSH now comprises 62% of all prospective hydropower capacity worldwide (including construction, pre-construction, and announced), totaling 690 gigawatts (GW), compared with 426 GW (38%) from conventional (non-PSH) hydropower facilities, according to the latest update of GEM’s Global Hydropower Tracker (GHT).
In addition, the GHT has been updated with its most comprehensive dataset yet, now covering over 1,000 new projects and all facilities over 30 MW, which accounts for 89% of global operating hydropower capacity.
PSH operates using two reservoirs at different elevations to store and release energy when needed, unlike conventional hydropower, which generates electricity directly from naturally flowing or stored water. PSH remains the most widely deployed form of long‑duration energy storage, supporting grid reliability and enabling greater integration of variable renewable sources such as wind and solar. PSH plants are typically designed to supply electricity for more than eight hours, whereas most large‑scale lithium‑ion batteries discharge for only two to four hours.
In the latest GHT data release, global PSH capacity grew by 12 GW over the past year, a 6.5% increase relative to last year’s total. Non‑PSH capacity added 51 GW year on year, representing a 4.9% increase. Although non‑PSH additions surpassed PSH in absolute terms, PSH continues to expand at a faster relative pace.
The largest year‑on‑year increases in newly operating PSH were recorded in China, the United Kingdom, and India, reflecting strong investment in long‑duration storage to support renewable integration. Of all prospective hydropower capacity worldwide (1,116 GW), PSH projects account for 690 GW, outweighing conventional projects (426 GW) by approximately 1.6 to 1. Across projects already under construction, 189 GW are PSH and 137 GW are non‑PSH.
Expanded tracker coverage
The latest GHT update represents its highest-coverage dataset to date, now encompassing more than 89% of global operating hydropower capacity, up from 85% in the 2025 release. A revised methodology lowers the minimum project-capacity threshold from 45 megawatts (MW) to 30 MW, adding over 1,000 new projects and 36.5 GW of additional tracked capacity — roughly double the total capacity of the operating hydro portfolio of Italy, the world’s twelfth-largest country by total installed hydropower. This expansion also incorporates data from four additional countries and territories, further strengthening the GHT’s global coverage. Lowering the threshold from 45 MW to 30 MW added a much higher amount of conventional hydro relative to PSH, largely because most PSH facilities have capacities above this range, with the operating PSH facility averaging ~600 MW.
- Eastern Asia leads all regions for operating PSH with 100.5 GW, followed by Western Europe (23.3 GW), Northern America (20.3 GW), and Southern Europe (20.1 GW).
- At the country level, China (68.3 GW), Japan (24.8 GW), and the United States (20.1 GW) operate the world’s largest PSH fleets.
- China, India, and the United States also lead in prospective PSH capacity. China’s total of 168 GW of PSH under construction is the largest in the world.
- In India, PSH represents 67% of all prospective hydropower capacity, underscoring a strong tilt toward storage-oriented buildouts.
- By contrast, Indonesia, Nepal, and Pakistan continue to prioritize conventional hydropower, each with at least 15 GW of prospective capacity but less than 20% PSH (Indonesia 19%, Nepal 10%, Pakistan 0%).
- In the United States, almost all prospective hydropower capacity is PSH, at 99%, indicating a near-exclusive focus on storage-based projects in the development pipeline.
Conventional hydropower remains a major contributor to the world’s energy systems, with 1,083 GW in operation across over 4,600 facilities of at least 30 MW, and an additional 426 GW in prospective stages globally. As pumped storage continues to shape the trajectory of hydropower development, GEM’s Global Hydropower Tracker offers granular, project‑level visibility into evolving trends in both conventional and PSH projects worldwide.
